1. Field of the Invention
This invention relates to an improvement to a binding machine and, more specifically, to a binding machine which binds documents using plastic strips.
2. Prior Art
This invention relates to a debinding apparatus for commercially available binding machines. Reference is made to U.S. Pat. No. 4,270,970 on a sheet binding apparatus. Generally, the system disclosed therein is for binding together, either temporarily or permanently, pluralities of sheets of paper. Each of the sheets is formed with a series of spaced apertures adjacent one margin thereof. The system uses a first strip having studs which correspond in spacing to the apertures in the sheets and a second strip formed with holes to receive the studs which are aligned with the apertures in the sheets. The machine incorporates a pressure bar which applies pressure on the sheets of paper while pressing the strips toward each other. A plurality of heated cutting elements, one for each stud, cuts off the excess lengths of the studs and initiates the formation of heads on the ends of the studs. An equal plurality of fingers engage the heated ends of the studs to form rivet heads thereon and to then cool the studs. These machines have proven commercially successful.
Binding machines have been provided with debinding functions. In this regard, see U.S. Pat. No. 3,756,625 where the machine's cycle can be stopped for a period of time for melting the rivet heads at the point where the heated cutting elements are closest to the rivet heads. When the cycle is resumed, however, the cooling fingers engage the ends of the studs to reform rivet heads and cool the plastic studs before the sheets can be removed from the machine for separation. The reformed rivet heads hinder debinding of the sheets.
Accordingly, a primary object of the present invention is to provide a binding machine using plastic strips which includes an apparatus for debinding of previously bound sheets.
Another object of the invention is to provide a binding machine of the above character which includes heated cutting elements which in the debinding cycle serve to soften the rivet heads previously formed on the ends of the studs during the binding cycle.
Another object of the invention is to provide a binding machine of the above character which in the debinding cycle deactivates the cooling fingers used during the binding cycle.